300
S. B. Jaffri and K. S. Ahmad
5 Characterization of Biomimetic NPs
For the validation of microbes mediated green NPs, number of analytical techniques are employed (Fig. 2). These techniques range from physicochemical to
bio-analytical ones. Different types of isolations methods have been used and microbial strains are derived from various sources, e.g., pedospheric samples, hot springs,
mountain samples, environmental isolates, and mangrove forest samples to mention
a few. They have been cultured by means of different assays on nutrient broths in
the biotechnological labs for utilization as bio-precursors for metallic NPs synthesis
after incubation at certain conditions. The microbial strains are also identified via
DNA analysis after isolation followed by PCR amplification and sequencing and
used accordingly. Usually, biogenic NPs are analyzed for optical parameters via
ultraviolet-visible spectrophotometry. The direct and indirect bandgaps (Eqs. 1 and
2, respectively) and other optical responses can also be calculated by using Tauc’s
plot from this technique.
α =
A(hv − E g )
2
hv
(1)
α =
A(hv − E g )
1/2
hv
(2)
Another widely used technique for analysis of vibrational parameters and presence
of organic functional groups is done via Fourier transform infrared spectroscopy in
a range of 400–4000 cm
−1 . Another similar technique is the utilization of Raman
Fig. 2 Different types of analytical techniques used for validation of microbial-mediated green
nanoparticles
S. B. Jaffri and K. S. Ahmad
5 Characterization of Biomimetic NPs
For the validation of microbes mediated green NPs, number of analytical techniques are employed (Fig. 2). These techniques range from physicochemical to
bio-analytical ones. Different types of isolations methods have been used and microbial strains are derived from various sources, e.g., pedospheric samples, hot springs,
mountain samples, environmental isolates, and mangrove forest samples to mention
a few. They have been cultured by means of different assays on nutrient broths in
the biotechnological labs for utilization as bio-precursors for metallic NPs synthesis
after incubation at certain conditions. The microbial strains are also identified via
DNA analysis after isolation followed by PCR amplification and sequencing and
used accordingly. Usually, biogenic NPs are analyzed for optical parameters via
ultraviolet-visible spectrophotometry. The direct and indirect bandgaps (Eqs. 1 and
2, respectively) and other optical responses can also be calculated by using Tauc’s
plot from this technique.
α =
A(hv − E g )
2
hv
(1)
α =
A(hv − E g )
1/2
hv
(2)
Another widely used technique for analysis of vibrational parameters and presence
of organic functional groups is done via Fourier transform infrared spectroscopy in
a range of 400–4000 cm
−1 . Another similar technique is the utilization of Raman
Fig. 2 Different types of analytical techniques used for validation of microbial-mediated green
nanoparticles